He stresses that the prayer team, which has met every Saturday for 10 years outside Coleraine Town Hall, does not make any promises or give any guarantees.

"Jesus heals - we don't. We just pray our best prayers. Not everyone gets healed, but we feel that more people are healed than not," he said.

"We only know of those who say at the time that they have been cured or that their condition has been improved, or those who come back to tell us that.

"We do not have any definitive numbers, but I believe that hundreds of people have been cured over the years of our ministry."

The church was highlighted this week when the mother of a Donaghadee teenager suffering from cancer described how he got out of his wheelchair and danced after attending a prayer session.

Kim Martin said Mark had noticed that one of her son Joshua's legs was shorter than the other, and that when the team prayed with him the leg "grew in front of our eyes".

Kim added: "I'm so glad my mum was there because she is the most cynical person you could meet and I'm not sure anybody would have believed me if I had been there on my own."

Mark elaborated: "I saw that spiritually there was a fog over his life and a lifelessness behind his eyes.

"I told him that I believed there would be a sign of what God could do in healing him of his cancer.

"He had complained of a pain going from his back into his leg, and as we began to pray his leg began to lengthen, the fog over him lifted and the life returned to his eyes.

"I knew at that moment that God had touched him.

"We never say that people have been cured. That is up to them to say. What I know is that he got out of his wheelchair. There was a spring in his step and he walked away pushing his wheelchair."

Mark tells of other examples of healing carried out through the HOTS ministry:

In a church in Wales weeks ago, he prayed with a man who had one leg longer than the other. "He said he didn't want to be taller," Mark said. "There was a crowd of people watching. I put one finger on the sole of his foot and as we prayed his leg began to shorten."

A 78-year-old man unable to walk properly came to the ministry in Coleraine. When the team prayed with the man, the pain left him, he got up and was able to walk. He spent 20 minutes telling passers-by that God had cured him. He gave Mark his walking stick as a souvenir.

A woman who had been attacked on the street was left unable to turn her head from side to side for nine years. But after coming to the ministry, she regained mobility.

Another woman, this one with long-standing fibromyalgia that had left her housebound for three years - "on a good day she could just push the start button on her washing machine" - was carried from her car to the prayer team. Two weeks later she returned telling them she had just been for a walk along the Giant's Causeway with her husband.

Mark founded the HOTS ministry in Coleraine at Easter in 2005 and spends much of his time travelling the world spreading his message to other churches.

It is a far cry from his earlier life. Born in South Africa 58 years ago, he came to England with his father when he was just three after his parents separated.

At university he graduated in graphic design, but he later specialised as a high-end interior designer working for rich London families.

"I was decorating the homes of these very wealthy people and really did enjoy it," he said. "It was a way of releasing my creativity."

After his father died when Mark was 30, he admits that his world crumbled.

Then a friend he had met at art college suggested to him that he came along to a service in an Elim church in Ilford.

"I refused a few times as Christianity and the Church were poles apart from my life then," Mark said. "Eventually I thought I would sneak in early, hide behind a pillar and then leave once the service was over.

"When I entered that church I had an encounter with God, although I didn't realise what it was at that time. It was like rays of sunlight wafting over me and inside me. I felt a warmth inside me I had never experienced before.

"When the service was over there was a pool of tears at my feet. I had wept throughout the service. I then decided to go to every meeting that I could.

"Two weeks later, under the ministry of an Anglican in a Pentecostal church, I surrendered my life to Christ and I have never looked back."

He later toured the UK with an evangelist and subsequently became an assistant minister at the same church he first went to.

Mark, his wife Linda and their three children Joshua, Timothy and Jordan came to Coleraine 17 years ago, but he spent almost seven of those working as a double glazing salesman.

"It was then that God began speaking to me about a new way of helping to teach the church how to share the love of God on the streets, and that was when HOTS was established.

"We have been on the steps of the town hall every Saturday come rain, hail, snow or sunshine since then. We put out chairs for those who want to be healed or who just want to pray with us. We believe that God will answer those prayers whatever they are for.

"We don't ask for anything or accept donations on the street. All we ask of people is a little bit of their time.

"The people who come to pray with us don't have to be Christians. We just show them God's love. It brings great peace to them.

"People come to us especially at this time of year, often just to chat or pray. So many people are under a lot of pressure these days."